The photocatalytic degradation of methyl orange using Fenton synergized by nanometer TiO2 was investigated. The influence of H2O2 concentration, initial concentration and pH of methyl orange on degradation efficiency was investigated, and the degradation kinetics was discussed. The results showed that, the synergistic effect to the degradation of methyl orange by Fenton synergized with nanometer TiO2 was observed. The photocatalytic degradation efficiency of 99.4%, which was 2.63 times alone by TiO2, 2.32 times alone by Fenton, 1.2 times of their geometrical accumulation at the some experiment...